/*
 * Copyright (c) Ian F. Darwin 1986-1995.
 * Software written by Ian F. Darwin and others;
 * maintained 1995-present by Christos Zoulas and others.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice immediately at the beginning of the file, without modification,
 *    this list of conditions, and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE FOR
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */
/*
 * fsmagic - magic based on filesystem info - directory, special files, etc.
 */

#include "file.h"

#ifndef  lint
FILE_RCSID("@(#)$File: fsmagic.c,v 1.67 2013/03/17 15:43:20 christos Exp $")
#endif  /* lint */

#include "magic.h"
#include <string.h>
#include <stdlib.h>

#include <folly/portability/Unistd.h>

/* Since major is a function on SVR4, we cannot use `ifndef major'.  */
#ifdef MAJOR_IN_MKDEV
# include <sys/mkdev.h>
# define HAVE_MAJOR
#endif
#ifdef MAJOR_IN_SYSMACROS
# include <sys/sysmacros.h>
# define HAVE_MAJOR
#endif
#ifdef major      /* Might be defined in sys/types.h.  */
# define HAVE_MAJOR
#endif

#ifndef HAVE_MAJOR
# define major(dev)  (((dev) >> 8) & 0xff)
# define minor(dev)  ((dev) & 0xff)
#endif
#undef HAVE_MAJOR

#ifdef PHP_WIN32

# undef S_IFIFO
#endif


#ifndef S_ISDIR
#define S_ISDIR(mode) ((mode) & _S_IFDIR)
#endif

#ifndef S_ISREG
#define S_ISREG(mode) ((mode) & _S_IFREG)
#endif

private int
handle_mime(struct magic_set *ms, int mime, const char *str)
{
  if ((mime & MAGIC_MIME_TYPE)) {
    if (file_printf(ms, "inode/%s", str) == -1)
      return -1;
    if ((mime & MAGIC_MIME_ENCODING) && file_printf(ms,
        "; charset=") == -1)
      return -1;
  }
  if ((mime & MAGIC_MIME_ENCODING) && file_printf(ms, "binary") == -1)
    return -1;
  return 0;
}

protected int
file_fsmagic(struct magic_set *ms, const char *fn, struct stat *sb, php_stream *stream)
{
  int ret, did = 0;
  int mime = ms->flags & MAGIC_MIME;

  if (ms->flags & MAGIC_APPLE)
    return 0;

  if (fn == NULL && !stream) {
    return 0;
  }

#define COMMA  (did++ ? ", " : "")

  HPHP::String name;
  if (stream) {
    name = stream->getName();
    fn = name.data();
  }
  auto w = HPHP::Stream::getWrapperFromURI(fn);
  if (!w || (w->stat(fn, sb) < 0)) {
    if (ms->flags & MAGIC_ERROR) {
      file_error(ms, errno, "cannot stat `%s'", fn);
      return -1;
    }
    return 1;
  }

  ret = 1;
  if (!mime) {
#ifdef S_ISUID
    if (sb->st_mode & S_ISUID)
      if (file_printf(ms, "%ssetuid", COMMA) == -1)
        return -1;
#endif
#ifdef S_ISGID
    if (sb->st_mode & S_ISGID)
      if (file_printf(ms, "%ssetgid", COMMA) == -1)
        return -1;
#endif
#ifdef S_ISVTX
    if (sb->st_mode & S_ISVTX)
      if (file_printf(ms, "%ssticky", COMMA) == -1)
        return -1;
#endif
  }

  switch (sb->st_mode & S_IFMT) {
#ifndef PHP_WIN32
# ifdef S_IFCHR
    case S_IFCHR:
      /*
       * If -s has been specified, treat character special files
       * like ordinary files.  Otherwise, just report that they
       * are block special files and go on to the next file.
       */
      if ((ms->flags & MAGIC_DEVICES) != 0) {
        ret = 0;
        break;
      }
      if (mime) {
        if (handle_mime(ms, mime, "x-character-device") == -1)
          return -1;
      } else {
#  ifdef HAVE_STAT_ST_RDEV
#   ifdef dv_unit
      if (file_printf(ms, "%scharacter special (%d/%d/%d)",
          COMMA, major(sb->st_rdev), dv_unit(sb->st_rdev),
            dv_subunit(sb->st_rdev)) == -1)
          return -1;
#   else
      if (file_printf(ms, "%scharacter special (%ld/%ld)",
          COMMA, (long)major(sb->st_rdev),
          (long)minor(sb->st_rdev)) == -1)
          return -1;
#   endif
#  else
      if (file_printf(ms, "%scharacter special", COMMA) == -1)
          return -1;
#  endif
      }
      return 1;
# endif
#endif

#ifdef  S_IFIFO
  case S_IFIFO:
    if ((ms->flags & MAGIC_DEVICES) != 0)
      break;
    if (mime) {
      if (handle_mime(ms, mime, "fifo") == -1)
        return -1;
    } else if (file_printf(ms, "%sfifo (named pipe)", COMMA) == -1)
      return -1;
    break;
#endif
#ifdef  S_IFDOOR
  case S_IFDOOR:
    if (mime) {
      if (handle_mime(ms, mime, "door") == -1)
        return -1;
    } else if (file_printf(ms, "%sdoor", COMMA) == -1)
      return -1;
    break;
#endif
#ifdef  S_IFLNK
  case S_IFLNK:
    /* stat is used, if it made here then the link is broken */
      if (ms->flags & MAGIC_ERROR) {
          file_error(ms, errno, "unreadable symlink `%s'", fn);
          return -1;
      }
  return 1;
#endif

#ifdef  S_IFSOCK
#ifndef __COHERENT__
  case S_IFSOCK:
    if (mime) {
      if (handle_mime(ms, mime, "socket") == -1)
        return -1;
    } else if (file_printf(ms, "%ssocket", COMMA) == -1)
      return -1;
    break;
#endif
#endif
    case S_IFREG:
  /*
   * regular file, check next possibility
   *
   * If stat() tells us the file has zero length, report here that
   * the file is empty, so we can skip all the work of opening and
   * reading the file.
     * But if the -s option has been given, we skip this
     * optimization, since on some systems, stat() reports zero
     * size for raw disk partitions. (If the block special device
     * really has zero length, the fact that it is empty will be
     * detected and reported correctly when we read the file.)
   */
  if ((ms->flags & MAGIC_DEVICES) == 0 && sb->st_size == 0) {
    if (mime) {
      if (handle_mime(ms, mime, "x-empty") == -1)
        return -1;
      } else if (file_printf(ms, "%sempty", COMMA) == -1)
      return -1;
      break;
  }
    ret = 0;
    break;

  default:
    file_error(ms, 0, "invalid mode 0%o", sb->st_mode);
    return -1;
    /*NOTREACHED*/
  }

  return ret;
}
